# Thread: instantaneous velocity/average velocity from looking at position graph

1. ## instantaneous velocity/average velocity from looking at position graph

I was having trouble getting this picture to be the right size, but the left hand side y axis has values of 50,100,150
X axis is labeled 2,4,6,8,10
The y axis represents distance in meters, x is time in seconds.
I am asked to order the following from least to greatest:
A. The instantaneous velocity at time 6 seconds.
B. The instantaneous velocity at time 9 seconds
C. the average velocity over the interval from 6- 8 seconds.

I know you can draw a tangent line for instantaneous velocity but this is hard for me to do with this picture.
How should I approach this problem? the average velocity appears to be about 5/2 but that's all I can get.
The correct answer is E and NOT A.
Answer E got cut off but it is B<C<A
This is an old quiz problem.
Can someone help me understand?

2. Originally Posted by calc67x

I was having trouble getting this picture to be the right size, but the left hand side y axis has values of 50,100,150
X axis is labeled 2,4,6,8,10
The y axis represents distance in meters, x is time in seconds.
I am asked to order the following from least to greatest:
A. The instantaneous velocity at time 6 seconds.
B. The instantaneous velocity at time 9 seconds
C. the average velocity over the interval from 6- 8 seconds.

I know you can draw a tangent line for instantaneous velocity but this is hard for me to do with this picture.
How should I approach this problem? the average velocity appears to be about 5/2 but that's all I can get.
The correct answer is E and NOT A.
Answer E got cut off but it is B<C<A
This is an old quiz problem.
Can someone help me understand?
The slope at B is negative; why did you not call that less than the others? They aren't asking about speed (the absolute value of velocity).

And can you explain why you think A < B < C?

I wouldn't bother calculating values; you can just visually estimate which is steeper. But giving numbers will help you explain your thinking.

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